This invention relates to a fluid sampling chamber assembly and, more particularly, to such a chamber for use in making noninvasive in-line measurements of fluid samples contained in the chamber.
It is well known to provide special chambers for making inline measurements of biological fluids, such as urine In U.S Pat. No. 4,417,585 of Frank, a pair of chambers are alternately, automatically filled with and then moved to a position to dump a urine sample into a collection bag while the other chamber is moved to a fill position. The volume collected is determined by counting the number of fill and dump cycles Similarly, in U.S patent application Ser. No 06/484,074, filed 4/11/83 of Silver, entitled "Liquid Drainage System With Light Emitters and Detectors", and assigned to the assignee of this application, inlet and outlet clamps are photo-optically controlled to successively fill and empty a tubular chamber to make volumetric measurements. Likewise, in U.S. Pat. No. 4,343,316 of Jesperson, a calibrated chamber of conical shape is contained within a housing to enable visual volumetric determinations. The level of the fluid within the sample chamber is sensed photo-optically to make volumetric measurements In U.S. Pat. No. 4,291,692 of Bowman et al. and U.S. Pat. No. 4,314,484 of Bowman, drop chambers for photooptical sensing are provided to make volumetric and rate measurements of collected urine.
While all of these chambers enable noninvasive, in-line monitoring of sample fluid in a collection system, none provides special sensor walls or the like which are physically engageable by sensor probes from a location from outside the chamber housing. In U.S. Pat. No. 4,418,565 of St. John, entitled "Ultrasonic Bubble Detector", bubbles are detected in a flexible tube by ultrasonic transducers on opposite sides thereof, but temporary storage of a sample is not possible.
Another disadvantage of known sampling chamber assemblies is that the fluid is collected in the sampling chamber only by means of sophisticated control circuitry for controlling the inlets and outlets thereto or through means of a movably mounted sampling chamber assembly which is subject to mechanical wear and failure. In addition, because of the fill and dump approach of many of these sampling chamber assemblies, the fluid sample cannot be continually refreshed with fresh sample fluid.